Find the area of the sector please

Given that abcd is a rhombus, what is the value of x?

Graph the line that represents a proportional relationship between d and t with the property that an increase of 33 units in t corresponds to an increase of 44 units in d. what is the unit rate of change of dd with respect to t? (that is, a change of 11 unit in t will correspond to a change of how many units in d? )

Having a hard time understanding this question (see attachment).